


Part 4: Switch

by addictcas



Series: Croatoan ABO 'verse [4]
Category: Supernatural
Genre: AU, AU: Endverse Dean is not a dick, Alpha Dean, Alpha/Beta/Omega Dynamics, Alternate Universe - Croatoan/Endverse, Anal Sex, Bossy Castiel, Bottom Alpha, Bottom Dean, Chuck Shurley is Not God, Claiming, Coming Untouched, Dom/sub Undertones, Episode: s05e04 The End, Established Relationship, Gentle Dom Castiel, Human Castiel, M/M, Mating Bond, Nearly Human Castiel, Non-Traditional Alpha/Beta/Omega Dynamics, Omega Castiel, Oral Sex, Post-Coital Cuddling, Self-Lubrication, Snarky Castiel, Stereotypes, Switching, Top Castiel, Top Castiel/Bottom Dean Winchester, True Mates, top omega, yes you read that correctly
Language: English
Status: Completed
Published: 2015-02-23
Updated: 2015-02-23
Packaged: 2018-03-14 19:07:39
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,826
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3422255
Author URL: https://archiveofourown.org/users/addictcas/pseuds/addictcas
Summary: <blockquote class="userstuff">
              <p>“You want to do <em>what now</em>?"</p><p>(Endverse AU) In which Dean is asked the strangest question he's ever heard, says no, then says yes, and then kinda-sorta likes the results.</p><p>(part of series but can be read alone)</p>
            </blockquote>





	Part 4: Switch

 

“You want to do _what now_?”

“You heard me, Dean.”

The alpha snaps his jaw shut because staring at Cas like a gaping fish is not ridding him of the look of sheer determination that's planted itself on the omega's stupidly attractive face.

“That's not—it doesn't work that way.”

Castiel crowds into Dean's space, backing him into the table. “Says who?” His voice has reached that husky, gravelly timbre that Dean hasn't heard since... well... since Cas was an angel.

“Says everyone! And... _biology_.”

The omega just shrugs, like he didn't just ask the weirdest fucking question Dean's ever heard in his life in regards to sex. And he's put on _panties_ , for God's sake.

“You may have forgotten, Dean, that I have a dick, too. One that is perfectly capable of anal penetration.”

The alpha scrubs a hand over his face, feeling the heat in his cheeks.

“Jesus, Cas. You don't follow the word 'dick' with things like 'anal penetration.'”

“My apologies,” his mate bites out sarcastically.

“Look, I'm sorry,” Dean says. “But no, not gonna happen.”

Cas huffs out an angry breath and grabs Dean's shirt collar, pulling him forward until their noses are almost touching.

“I dragged your sorry ass out of the depths of Hell. I single-handedly tore through armies of demons when other angels turned and ran.”

Again with the fucking guilt trip. Too bad it works every time. “I know, Cas.”

“I know you more intimately than any other person on this planet ever has, and ever will.” Castiel's expression softens and he plants a brief kiss on his mate's lips. “I want you to know what it feels like to give up your alpha instincts, to be vulnerable.”

And then Cas is giving him that look, the one Dean can never say no to. The look that gets Dean to practice yoga on Sundays with him (just the two of them—Dean will take that secret to his grave), the look that got Dean to cut his alcohol consumption in half, even though Cas continues his drug use (Dean apparently has not mastered the doe-eyed, pleading expression his mate throws him when he wants something).

Dean caves.

“Fine,” he groans, feeling his cheeks flush. “Fucking—Jesus, fuck. Fine.”

His omega beams at him and Dean can pick up just from his scent how pleased he is.

“Just this once,” Dean clarifies.

“Deal.” Cas pecks him on the cheek.

“And you have to go slow.”

“Deal.” He nuzzles into the alpha's neck.

“And _nobody_ gets to know about it.”

Castiel pulls away, looking offended. “Of course, Dean. Don't you trust me?”

Dean kinda feels like shit at that. “You know I do, Cas. This is just... this is really weird for me, okay? I need a minute to wrap my head around it.”

“Take your time.” The omega's happy scent does not fade but becomes overlapped with a faint smell of arousal.

Dean finds comfort in that and tries to gain control of his breathing; it's become shaky. Dean Winchester, alpha, taking it up the ass like an omega. Like a—no, Dean doesn't view omegas as bitches. But society does, and if word got out he'd—but word is not gonna get out because Cas would never do that to him. Dean trusts his mate, more than he's ever trusted anyone else in his life, ever, and he can do this. He'll do this, just one time. He'll try it, for Cas.

“While you're mulling things over, I'll just...” the omega latches onto Dean's neck, sucking at his flesh and most likely leaving large, dark marks. Castiel, former angel of the Lord and alpha at heart, positively gets off on marking his claim. It helps Dean relax, just a little, focusing on the mouth that's licking and nipping, sending blood rushing south despite the alpha's nervousness. He walks Cas backward towards the bed, ridding them both of their shirts before pushing the omega into the mattress.

Dean's senses are overwhelmed by the sugary scent of slick, and he's shaking with the instinctual need to delve into that tight heat. He growls and lowers himself down over his mate, grinding their erections together.

“Easy, Dean,” Cas tells him, rolling them until Dean is on his back. “Give up control. Let me lead.”

It's not that that's anything new; the omega often displays dominance in the bedroom, but this is leading to something much different, something terrifying. The fallen angel must smell the fear because he kisses Dean's forehead softly, saying, “Relax. I'm going to make this good for you.” Then he presses another kiss to Dean's mouth, adding, “This won't make you any less of a badass.”

Dean laughs as his mate smirks, and he doesn't complain when his pants and boxers are pulled down in one swift motion. The cool night air only hits his cock for a second before Cas' mouth is on him. Dean immediately feels some of the tension in his body fading as panic starts easing away.

After a minute or so Castiel pops off of him and asks, “Have you ever fingered yourself? Or used any toys?”

“No, Cas. Shit,” Dean says as if the question is ridiculous. Because it is.

“It would be perfectly normal if you had.” Cas starts stroking him with his fist, looking up at Dean like he's going to make some big gay breakthrough with him.

“Look, save it for Dr. Phil, alright?” Is Dr. Phil even still alive? Dean read somewhere a while back that he'd been a demon all along, but that was probably in the Inquirer or some other shitty tabloid that positively soaked up all of the demonic apocalypse gossip. Either way, the idea of that bald son of a bitch with black eyes is immensely entertaining.

“I don't know who that is,” the omega says, tilting his head the way he always does when human things baffle him.

And that's one of the things Dean loves about Cas. He may have gained serious experience points in the down-and-dirty aspects of humanity—sex, drugs, violence—but he's still so goddamn clueless when it comes to pop culture.

“He's a—you know what, never mind. I'm just saying, less talk and more... you know. Let's just get this over with.”

“As you wish,” the Castiel says with that pissy attitude he acquires when he's 100% done with Dean's bullshit. He reaches down between his own legs and pulls his fingers back covered in slick, and _holy shit_ this is actually happening.

Dean jumps at the first touch against his rim and tries to hold still. There's no intrusion yet, just light circling. Cas is testing the waters, waiting for the all clear. Dean swallows loudly, then nods his head.

It's not comfortable when his mate slides in to the first knuckle, but he's gratefully distracted by the sinful mouth that's resumed sucking him off. He's being too gentle, though; Dean can take it. His hesitance is about pride, not pain.

“Come on, Cas. I can take more. I'm not made of porcelain."

The omega pulls his hand away to gather more slick, and then there are two fingers inside of him, as deep as they can get. At the same time, Cas does that thing with his tongue that, without fail, turns all of Dean's muscles into jelly. He tries to focus that relaxation into the muscles that is mate is currently scissoring open while making all sorts of happy noises that vibrate pleasantly through Dean's dick. The alpha is surprisingly hard as hell, despite his trepidation about the current situation. He decides to store that observation away for further contemplation when suddenly Cas crooks his fingers and—oh. Then Dean's back is arching and he's making a sound that should be embarrassing but he's too focused on how amazing it feels.

Cas pulls off of his cock to smirk at him (bastard) and adds a third finger and it's starting to feel... not so bad. He's even—no, not possible. He's certainly not looking forward to having more of his mate filling him up, because he's an alpha, and alphas don't like that shit. Except maybe Dean sorta does.

He grabs his omega by the hair and drags him up for a searing kiss, mumbling, “Do it,” into Cas' mouth.

Castiel coats himself in a generous amount of slick, the smell of which is intoxicating, moaning as he strokes his length a few times. The sight, combined with the thick hormone scents, has Dean's head spinning and his dick throbbing.

Dean is amazed by the control his mate is showing as he lines up and pushes in, so slowly, letting out a shaky breath as he drops his forehead to Dean's shoulder.

Now the alpha is craving more, wants the omega to _move_ , wants that spot hit again. “Come on, baby. Fuck me already.”

Cas presses a kiss to his mate's collarbone, pulling out almost all of the way before slamming back in, making sparks flash behind Dean's eyelids. After a few steady thrusts, he tilts the alpha's hips up. Dean wraps his legs around Cas' waist, and then his prostate is being hit with every roll of hips.

They're bending the rules, giving the finger to society, and it's exhilarating.

“Fuck, Cas. Yes, yes. God.”

Dean digs his nails into the omega's back, hard enough to break skin as Castiel's pace becomes ruthless, pushing Dean up the bed and bunching up the slick-soaked sheets.

“So beautiful like this, Dean.” The alpha almost protests out load, because he doesn't like being called that, but Cas sounds so blissed-out that he lets it slide. “All for me.”

“Just for you, Cas,” Dean gasps as his mate hits that spot, hard, and then waves of heat are pulsing through his body as he comes untouched, and isn't that the shock of the century.

“Always for my mate,” he whispers, once he's caught his breath.

It's the sappy stuff that always pushes Cas over the edge (Dean has trained himself to accommodate him, as strange as it felt the first few times), and tonight is no exception. The omega trembles as he rocks into Dean through his orgasm. He collapses on top of his mate, pulling out.

“Thank you, Dean," he says, eyes wide. "That was wonderful.”

“Yeah, yeah,” Dean says. He feels come leaking out of him, and it's really strange, so he extricates himself to go clean up in the bathroom. When he gets back with a wet rag to wipe up the mess on Cas, too, his omega's eyes are closed and there's a sleepy smile on his face. Dean wants to tell him to savor the afterglow, to not get used to topping. But maybe that's not entirely the truth anymore.

Maybe, just maybe, they can do this again someday. _For Cas, of course,_ Dean tells himself, pulling his mate against his chest.


End file.
